Question: A jar contains $7$ red balls, $6$ green balls, and $4$ blue balls. If a ball is randomly chosen, what is the probability that it is not green?
Solution: There are $7 + 6 + 4 = 17$ balls in the jar. There are $6$ green balls. That means $17 - 6 = 11$ are not green. The probability is $ \frac{11}{17}$.